CMD-K doesn't work if the summary record is active

After a single total (or similar) operation in a data sheet, the summary record is active and CMD-K has no effect. With another record active, it works. Is this intentional?

I would say that is a minor bug. Interestingly, choosing Remove All Summaries from the menu does work. It also works if you click on another record and the click back to the summary record, or click on another window and then click back to the data sheet, or simply click on the menu bar but don’t select anything. In fact clicking ANYWHERE, even the current cell, will make it work. The same problem occurs if you use the Group command and then immediately press Command-K. I think that the menu bar isn’t actually updated until there is a click, so the Command key equivalent doesn’t actually exist yet. I’ve added this to the issue tracker.